X-ray tube.



M. S. GLAWSON.

X-RAY TUBE.

APPLIOATION FILED $EPT. 9. 1913.

1,1 32,442. Patented Mar. 16, 1915.

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MONROE S. CLAWSON, OF WEEHAWKEN, NEW JERSEY.

X-RAY TUBE.

Specification of Letters Patent.

Patented Mar. 16, 1915 Application filed September 9, 1913. Serial No. 788,946.

To all whom it may concern:

Be it known that I, MONROE S. CLAwsoN, a citizen of the United States, residing at Weehawken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in X-Ray Tubes, of which the following is a specification.

My invention relates to X-ray tubes and has special reference to an improved construction of the anode.

As is well known in the art in the operation of an X-ray tube the cathode stream focuses at a point on the anode and generates a very high temperature, thus necessitating the use of a metal not readily fusible. The metal found to be suitable and most commonly used now is tungsten which is embedded in a large piece of copper to form the anode. The reason for employing copper is that this metal radiates heat well and is consequently especially adapted for the purpose. Tungsten is known to radiate heat poorly and has a high expansion co-efiicient so that it does not give up its heat as readily as desired. The difference in the expansion co-efficient of copper and tungsten renders the contact of the two metals very poor after a tube has been in operation so long that considerable heat has been generated at the anode, and it has been found that it is very desirable to have good contact between the tungsten and copper, or other metal, to facilitate the radiation of the heat from the tungsten to the copper as rapidly as possible.

My present invention has been designed broadly to obviate these objectionable features and has for its specific object the provision of a novel form of anode comprising a base or foundation metal of copper or other metal possessing the same qualities and provided with a button preferably of tungsten formed of such a shape that it presents a maximum degree of surface where it contacts with the foundation metal.

Referring to the drawings forming a part of this specification and in which several embodiments of my invention are illustrated: Figure 1 is a view of my improved X-ray anode, showing my invention in its simplest form, Figs. 2, 3, 4 and 5 are similar views showing modified forms, Fig. 6 is a front view of the preferred form of the but ton detached, Fig. 7 is a rear view thereof, Fig. 8 is a front view of a modified form of button showing curved corrugations, and 1 lg. 9 IS a rear view of still a different form of button showing corrugations in two directions.

Referring more particularly to the drawlogs and especially to Fig. 1, the numeral 1 designates the main or body portion of the anode formed preferably of copper, having the inclined face 2 as is commonly the case. A button 3, preferably of tungsten, is embedded in the body portion 1 flush with the lncllned surface 2. The button 3 is preferably circular and has its periphery 4 beveled, as shown, and provided with corrugations 5 which may be sharply angular in form as shown in Fig. 6, or curved, as shown in Fig. 8. The front face 6 of the button 3 is formed preferably smooth and the rear face 7 is corrugated, as shown in Fig. 7, or 1t may be provided with two sets of corrugations disposed at right angles to each other, as shown in Fig. 9. This anode may be conveniently made by molding the body portion 1 around the button 3. From this construction it will be obvious that by 'bevel ing the periphery 4 of the button the area is increased and that by corrugating the periphery 4 and the rear face 7 the maximum area is presented to contact with the body portion 1 of the anode, thus greatly facilitating the radiation of the heat generated at the focus of the cathode stream to the body portion of the anode.

In Figs. 2, 3, 4 and 5, I have shown my button embedded in a ring which has a corrugated surface which contacts with the corrugated surface of the body portion of the anode as shown. This ring is to facilitate the radiation of the heat of the button to the copper body and is preferably made of silver as it conducts heat more rapidly than copper.

Referring specifically to Fig. 2, the body portion 1 of the anode has its inclined surface 8 provided with corrugations, as shown. A ring 9, preferably of silver, and provided with corrugations upon its rear face is disposed upon said inclined surface 8 and has embedded therein the button 3 which also contacts with the surface 8. In this form the silver ring would be preferably cast around the button 3 and then the whole would be brazed onto the inclined surface 8 of the body portion 1.

In Fig. 3 the construction is similar to that in Fig. 2 except that the button 3 does not extend all the way through the ring 9 and consequently does not contact with the body portion 1.

In'Fig. 4 the body portion 1 is provided upon its inclined surface 10 with a pocket 11 within which is adapted to be brazed a ring 12 having its periphery and rear face corrugated. The button 3 is embedded in the ring 12, as shown.

In Figs. 2, 3 and t the outer face 6 of the button 3 is flush with the outer surface of the ring whereas in Fig. 5 the button 3 is sunk into the ring 13 in order that its outer face 6 is disposed in a plane below the outer surface of the ring. In other respects the construction in Fig. 5 is identical with that of Fig. 3, though it will be noted that in this form the button 3 may be brazed into the ring 13 instead of having the ring cast around it.

It will be understood that although I have described my improved anode as consisting of elements of copper and tungsten, or copper, silver and tungsten, I reserve the right to employ any other suitable material. I may also secure the buttons and the rings upon the anode and also the buttons upon the rings in any suitable manner, although I have described for the sake of clearness, casting and brazing. It will also be understood that although I have shown and described sharply angular and curved corrugations, I may employ any arrangement of corrugations upon the periphery and rear face of my button.

Having thus described my invention what I claim is:

1. An anode for X-ray tubes comprising-a body portion and a button of a different metal contacting therewith, said button having its periphery beveled and provided with corrugations to increase the area of the contacting surfaces.

2. An anode for X-ray tubes comprising a body portion and a button of a difierent material embedded therein, said button having its periphery and rear face provided with corrugations for presenting the maximum area along the surfaces contacting with the body portion.

3. An anode for X-ray tubes comprising a body portion, a ring formed of a different metal contacting therewith, said ring having its contacting surfaces corrugated to .provide a maximum area, and a button of still a different material embedded in said ring, said button being corrugated to provide a maximum contacting surface.

4. An anode for X-ray tubes comprising a body portion, a ring formed of a difi'erent material contacting therewith, said ring having its contacting surfaces corrugated to provide a maximum area, and a button of a still difierent material embedded in said signature in the presence of two Witnesses.

MONROE S. CLAWSQN. Witnesses:

ANNIE L. CLAWSON, E. MABEL Gonna. 

